Recurrent bacteremia caused by a 'Flexispira'-like organism in a patient with X-linked (Bruton's) agammaglobulinemia

Abstract

Helicobacter spp., except for Helicobacter cinaedi, have only rarely been reported in cases of septicemia. A patient with X-linked (Bruton's) agammaglobulinemia was found to have persistent sepsis with a Helicobacter- like organism despite multiple courses of antibiotics. His periods of sepsis were associated with leg swelling thought to be consistent with cellulitis. The organism was fastidious and required a microaerophilic environment containing H2 for growth. Optimal growth was observed at 35 to 37°C on sheep blood, CDC anaerobe, and Bordet-Gengou agars. Serial subcultures every 4 to 5 days were required to maintain viability. The organism was strongly urease positive and showed highest relatedness to Helicobacter-like organisms with the vernacular name 'Flexispira rappini' by 16S rRNA gene sequence analysis. Genomic DNA hybridization studies, however, found 24 to 37% relatedness to 'F. rappini' and even less to other Helicobacter spp. Although the organism phenotypically resembles 'Flexispira' and Helicobacter, it is thought to represent a new taxon. The patient's infection was eventually cleared with a prolonged (5-month) course of intravenous imipenem and gentamicin.